(NOT APPLICABLE)
The present invention relates to a new machine for accessing elevated surfaces that are inaccessible from inside a platform with fixed rails. Combining two technologies to create a machine with new capabilities produces this machine. These combined technologies are the aerial work platform and the fall arresting safety system. With this machine, a person will be able to use the aerial work platform capability to reach an elevated location and then use the safety of the fall arrest system to exit the platform and perform the required tasks.
When a worker cannot access the location of the work, the worker may unhook from the platform to access the work area. This situation is dangerous because the worker is not protected from a fall. The problem occurs when the platform cannot fit past some obstacle or the platform itself is an obstacle because of the fixed rails. One example of this occurs in the maintenance of aircraft. Aircraft maintenance often requires mechanics to access parts of the aircraft that cannot be accessed from within a platform. These surfaces are the top of the fuselage and the horizontal wing surfaces. See FIGS. 1-3.
Current aerial work platforms constrain the operator to work inside a guard rail structure. These aerial lifts have platforms with many shapes and many sizes, but all constrain the operator to stay within the rails of the platform. Current fall arrest systems are attached to fixed structures such as building trusses and beams or self-supporting fixed structures, and because of this, these systems do not position the operator. The operator must then gain access to an elevated surface by some other means (such as climbing a ladder or scaffolding) and then attach to the fall arrest system. A range of solutions is available for fall protection that are so-called xe2x80x9cfall restraintxe2x80x9d systems and not fall arrest systems. Fall arrest systems are designed to safely catch a person that is falling. A fall restraint system is designed to limit the movement of a person so that they cannot encounter a fall. The fall restraint system does not protect or catch a person that is falling. That is, a fall restraint system consists of the equipment used to keep an employee from reaching a fall point, such as the edge of a roof or the edge of an elevated working surface. The most commonly utilized fall restraint system is a standard guardrail. A tie off system that xe2x80x9crestrainsxe2x80x9d the employee from falling off an elevated working surface is another type of fall restraint.
In contrast, according to the definition in the Federal OSHA standard, a personal fall arrest system means a system used to arrest an employee in a fall from a working level. It consists of an anchor point, connectors, a body belt or body harness and may include a lanyard, deceleration device, lifeline, or suitable combinations of these. The entire system must be capable of withstanding the tremendous impact forces involved in stopping or arresting the fall. The forces increase with the fall distance due to acceleration. Federal OSHA standards govern structural requirements of fall arrest systems.
Many solutions for accessing elevated surfaces are available but none have the combination of providing access with a rotating telescoping boom and uninterrupted fall protection inside and outside the platform. For example, a fixed structure may be used to access elevated surfaces, and the fall arrest system can be attached to this structure. Examples are general scaffolding and structures similar to scaffolding which are specialized for certain applications. These fixed structures, however, do not provide flexible access and do not provide fall protection while accessing the work area.
Sometimes specialized structures are used for accessing aircraft. These structures conform to the shape of the airplane and have some limited flexibility to adjust for changing aircraft shape. These structures do not offer fall protection, but rather only fall restraint.
Self-retracting lifelines can be used as part of a fall arrest system by suspending them from a fixed point. These reels can be suspended from ceiling trusses, cranes, and fixed structures. Mobile structures are also used but they are fixed in shape and difficult to position.
Platforms are available that have side rails extending beyond the floor of the platform. The rails can then be located over a surface and the worker can walk on the surface with the rails surrounding him. The worker is protected from falling by the rails. This is a fall restraint system, however, and not a fall arrest system. In order for these platforms to be effective, the surface must be nearly flat to prevent a worker from sliding between the bottom of the railing and the work surface. Also, the worker cannot exit the rail perimeter. See, for example, FIGS. 4 and 5.
In an exemplary embodiment of the invention, a fall arrest platform includes a platform cooperable with a lifting vehicle and a fall arrest system. The platform includes a floor, safety rails surrounding a perimeter of the floor, and an entrance gate in the side rails. The fall arrest system is integrated with the platform and includes a lanyard securable at one end to a user""s harness, a lanyard connection securably receiving an opposite end of the lanyard, and mounting structure secured to the platform that supports the lanyard connection. The mounting structure movably supports the lanyard connection such that the user can move about a periphery of the platform.
In one embodiment, the mounting structure includes a wire rope secured about the safety rails, where the lanyard connection is movably mounted to the wire rope. Alternatively, the mounting structure may include a vertically mounted jib arm secured to the platform and extending above the user, wherein the jib arm supports the lanyard connection. In this context, the lanyard connection and the lanyard may comprise a housing and a self-retracting line disposed in the housing.
The entrance gate preferably includes a pivoting gate bar and a corresponding gate latch such that the user can attach the lanyard before entering the platform.
The platform may additionally include a compressed air accessory for power tools, the compressed air accessory including a compressed air hose mountable to the lifting vehicle and coupleable with either an onboard compressor or an external source of compressed air. Additionally, a power source for the compressed air accessory includes either an onboard engine-driven generator or an external AC power outlet.